This project proposes to evaluate the anti-inflammation effects of human milk feeding through free approaches: 1) Examination of human milk feeding effects and feeding of purified mil anti-inflammatory components on inflammation using animal models of inflammation; 2) in vitro studies of rat intestinal cell (target cell) and neutrophil (mediator cell) cellular responses to injury, and modulation of these responses by milk and milk anti-inflammatory components; 3) examination of the relationships between human milk content of anti-inflammatory components, urinary excretion of anti-inflammatory components by breast-fed infants and the degree of inflammation associated with illnesses in breast-fed infants. Each approach will emphasize the roles of the interleukin-1 receptor antagonist (IL-1RA) and soluble forms of the p55 and p75 TNFalpha receptors (sTNF RI and sTNF RII, respectively) in altering inflammatory responses following bowel injury (animal studies), and in the relationships between amounts fed, amounts excreted by the infant, and occurrence of illness. By defining these roles and relationships, we will establish a basis for progression to future studies examining infant feeding with formulas supplemented with anti-inflammatory components.